Operating System
Q61.
An operating system uses the Banker's algorithm for deadlock avoidance when managing the allocation of three resource types X, Y, and Z to three processes P0, P1, and P2. The table given below presents the current system state. Here, the Allocation matrix shows the current number of resources of each type allocated to each process and the Max matrix shows the maximum number of resources of each type required by each process during its execution. There are 3 units of type X, 2 units of type Y and 2 units of type Z still available. The system is currently in a safe state. Consider the following independent requests for additional resources in the current state: REQ1: P0 requests 0 units of X, 0 units of Y and 2 units of Z REQ2: P1 requests 2 units of x, 0 units of Y and 0 units of Z Which one of the following is TRUE?Q62.
Consider a system having "n" resources of same type. These resources are shared by 3 processes, A, B, C. These have peak demands of 3, 4, and 6 respectively. For what value of "n" deadlock won't occurQ63.
A system has n resources R_{0},...R_{n-1}, and k processes P_{0},...P_{k-1}. The implementation of the resource request logic of each process P_{i} is as follows: if (i%2= = 0) { if (i\ltn) request R_{i} ; if (i+2\ltn)request R_{i+2}; } else { if (i\ltn) request R_{n-i}; if (i+2\ltn)request R_{n-i-2} ; } In which one of the following situations is a deadlock possible?Q64.
A system has 6 identical resources and N processes competing for them. Each process can request atmost 2 resources. Which one of the following values of N could lead to a deadlock?Q65.
A single processor system has three resource types X, Y and Z, which are shared by three processes. There are 5 units of each resource type. Consider the following scenario, where the column alloc denotes the number of units of each resource type allocated to each process, and the column request denotes the number of units of each resource type requested by a process in order to complete execution. Which of these processes will finish LAST?Q66.
What is the minimum number of resources required to ensure that deadlock will never occur, if there are currently three processes P_{1},P_{2} and P_{3} running in a system whose maximum demand for the resources of same type are 3, 4, and 5 respectively.Q67.
Consider a system having 'm' resources of the same type. The resources are shared by 3 processes A, B, C, which have peak time demands of 3, 4, 6 respectively. The minimum value of 'm' that ensures that deadlock will never occur isQ69.
An operating system implements a policy that requires a process to release all resources before making a request for another resource. Select the TRUE statement from the following:Q70.
Consider the following snapshot of a system running n processes. Process i is holding x_{i} instances of a resource R, for 1\leq i\leq n. Currently, all instances of R are occupied. Further, for all i , process i has placed a request for an additional y_{i}, instances while holding the x_{i} instances it already has, There are exactly two processes p and q such that y_{p}=y_{q}=0. Which one of the following can serve as a necessary condition to guarantee that the system is not approaching a deadlock?